Myths and Narratives

Pray tell why some Husseini "progressives" are so cocksure of their narrative as if they have got the CCTV footage of Karbala battle and related events. There are myths, there are facts, there are cherry picked facts, and there are narratives based on cherry picked facts. Different narratives exist even for events that have happened very recently with each side using latest technologies to unravel and present their side of facts and opinions. Why should one not question the "one and the only one true version" of something that happened 14 centuries ago and is communicated to us though a chain of poorly documented accounts compiled by partisan authors that contains facts and myths both shrouded in the halo of reverence?  Wasn't Ahle-bait's claim to Imamate based on the same principle (i.e. hereditary dynasty) that Ummayads invoked to claim their Caliphate? Or Ummayads were the Caesars seeking dictatorships and Imam Hussein was the Brutus who was leading a "peoples' revolution" for the restoration of a "pure" Islamic republic based on universal suffrage?